Don,
I thought long and hard about it but my particular kit was just really light! This thing flies like a darn foamy..... It' just under 9 pounds. Most of them aren't that light and I didn't feel like beefing up "air!" I'd be dead serious saying that this thing would probably blow apart with a 180. I have built three of them and they were all over 10 1/2 to 11 pounds. You must have gotten one with some dense wood that could take the weight of those bigger motors. We used a MVVS 26 gasser a Saito 150 and a Saito 180 on the others. The one with the 180 got a Saito 220 to break in for a while and it was just plain insane...........
Terry